# Questions tagged [numerical-value]

Question relating numerical representations, operations and methods, including approximate results instead of exact symbolic results.

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### Solve Laplace equation in Cylindrical - Polar Coordinates

Hey mathematica stackexchange!! I've got a (possibly stupid) problem. I've tried many things to no avail, and I've read every post I've found on Laplace's equation. Background: I'm trying to find the ...
3k views

### Could I define 0^0 to be 1? [duplicate]

Many occasions, where I need to work numerically with functions. For a variable strictly between 0 and 1, during the optimization, it could become 0.^0 or 0^0, which then become indeterminate. Is ...
181 views

### Mathematica and IBVP mixing temporal and spatial derivatives

The following PDE's-system-solving code ...
259 views

### How can one generate an open-ended sequence of low-discrepancy points in 3D?

I'd like a low-discrepancy sequence of points over a 3D-hypercube $[-1,1]^3$, but don't want to have to commit to a fixed number $n$ of points beforehand, that is just see how the numerical ...
549 views

### Recognize physical constants?

Is there some way to ask Mathematica to recognize physical constants, such as 32 or 9.81 (gravitational acceleration, in different units, at Earth's surface)? I have in mind something like the "...
238 views

### Different Methods in NIntegrate

I am trying to numerically calculate a multidimensional integral which involves Jacobi elliptic theta functions. The integrand is the following: ...
588 views

### How to obtain numerical solutions of a two-variable equation?

I have a two-variable function: f[x_, y_] := (4 y^2 - 6) (Cos[y π] Cos[x] - Cos[2 y π] Sin[x]) How can I find all the numerical solutions for $x$ and $y$ such ...
442 views

### Re-arranging / selecting of a data table very slow in For loop [duplicate]

My task is quite simple; I have a table of data like M = {{1,2}, {1,3}, {3,4}, {5,1}, {6,9}, {6,8}, {6,1}}; so the table is sorted with respect to the first ...
1k views

### Why is 1. x (Times[1.`, x]) not simplified to x?

This is maybe a silly question, but I could not think of any logical reason why it is not simplified automatically. I was working with a big linear equation system with some constrained inequalities ...
827 views

### Error and uncertainty propagation: Is using Precision/Accuracy a sound strategy?

Questions What are the available resources to deal with experimental error and uncertainty propagation in Mathematica? Given that Mathematica already uses linearized model of error propagation on ...
740 views

### GroupBy twice gives different results

Bug introduced in 7.0 or earlier and persisting through 11.1 It took me quite a lot of time to finally trace down to this strange output. I really don't know why. First, I create a list ...
468 views

### Solving an equation approximately

I have a complicated equation in terms of $\omega$ and $\kappa$: ...
721 views

### Fixed-Point Numbers in Mathematica

I am working with a library that needs input in a Fixed Point notation. I’d like to figure out a way to convert the floating point results into fixed point representation. The fixed point length is ...
103 views

### Laplace equation DirichletCondition ignored

My goal is to find out force between two parallel identical disks with Voltage difference. To solve this, I tried to use laplace equation. And below is my code. where R is radius of disks, d is ...
2k views

### How to use NIntegrate in a function using parameters from a list

I would like to use NIntegrate in a function with some parameters from a list. I simplified my problem for this forum. The list of parameters is as follows: ...
366 views

### Why does N[Re@f] give complex result?

Consider this code: ...
242 views

### How to plot output data of Do-command?

The following in a simple numerical solution of the simple harmonic oscillator. ...
131 views

### 1-D PDE with nonlinear ODE as boundary condition

Recently, I am trying to solve a 1-D PDE with a nonlinear boundary condition using the function NDSolveValue. However, it seems that MMA (12) cannot solve it directly with some computational issues. ...
134 views

### Role of Accuracy in numerical evaluations, SplitBy vs GatherBy

This is a follow-up question to this question. I generated a list by substituting the results of a solve[] routine and set: ...
128 views

### Solve a system of 4-th order polynomial equations (numerically)

I have a function defined on $S^6 \times S^6$ (two spheres embedded in $\mathbb{R}^7$ individually). Let us call this vector $\vec{f}(\vec{x},\vec{y})$, where $\vec{x}$ and $\vec{y}$ are ...
764 views

### Center column heading in TableForm

I have a TableForm as follows: ...
82 views

### Why the data from Do-command disagree with the plot I get using them? [closed]

This is a question relevant to How to plot output data of Do-command? The Differential Equation at hand now is $\frac{d^2 f}{dx^2} + \frac{2}{x+0.1} \frac{df}{dx} = k(f)$ I give the code with the ...
I have a product Exp[-I*Pi*x]*BesselK[-1, 2.43*Ix]. Now, Exp[-I*Pi*x] grows larger and larger as $x$ increases for imaginary ...